Excavator tooth assemblies mounted to the cutting lip of excavator buckets and the like generally comprise a replaceable digging tooth and an adaptor which is secured by welding or the like to the cutting lip of a bucket or the like. The adaptor may in some instance comprise an adaptor body and an adaptor nose welded to the lip. The adaptor body has a socket-like recess at its rear end to receivably locate a spigot portion of the adaptor nose. The digging tooth is mounted to the front end of the adaptor body.
In use, excavator teeth and adaptors are subjected to extensive load forces along a longitudinal axis as well as in vertical and transverse directions. A snug fit is required between the digging point and the front portion of the adaptor and also between the adaptor socket and the nose spigot portion and their respective mounting pins to avoid premature wear between the components. As the various components wear, the locking pins can loosen thereby increasing the risk of loss of a digging point or an entire adaptor/tooth combination. This necessitates considerable downtime to replace the lost wear members and where items such as locking pins are not recovered, these can cause damage and/or further downtime in downstream operations such as ore crushing and the like.
The greatest loads experienced by excavator tooth assemblies are vertical loads which tend to generate large moment forces capable of rotating a tooth off the front of an adaptor and/or rotating the adaptor off the adaptor nose. In addition, sideways and twisting loads are frequently imposed on such tooth assemblies.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.